Sizing composition



Patented June 29, 1937 i'raE D STATES SIZING COMPO SITION Donald A. Rankin, Newburgh, N. Y., assignor to E. ll. du Pont de Nemours & Company, Wilmington, DeL, a corporation of Delaware No Drawing. Application March 30, 1934, Serial No. 718,207

13 Claims. (Cl. 154-40) This invention relates to a composition of matter for application to coated materials used for purposes where it is essential to decorate the surface of the coated material .with genuine gold or to adhere paper, fabric, or similar materials to the surface with ordinary commercial pastes and glues, and more particularly to the use of such materials in the bookbinding art.

Woven or non-woven fibrous bases coated with cellulose derivative compositions are used extensively in the bookbinding art because of certain desirable properties, for example, they are easily Worked in the bindery; may be easily cleaned, and in general withstand hard usage. There are, however, certain disadvantages to its use particularly in the bindery which makes certain methods of working highly desirable. The principal disadvantage is in the inability of the material to permit adhesion of genuine gold leaf to the surface when applied by means of heated dies, and the further inability to obtain adhesion of paper or similar materials directly on the coated surface with..the regular aqueous adhesives commonly employed.

The usual bindery practice is to treat the surface to which either the gold leaf or other metallic leaf is to be adhered with a suitable material Which will sufllciently reduce the surface tension between the two surfaces to be adhered, and permit satisfactory adhesion of the metal leaf or paper to the surface.

Various materials are used for this purpose, a.

ent No. 1,656,284 is described a product so madeas to permit stamping of gold or other metallic leaves to the surface and suitable adhesion of paper to the surface without any preliminary treatment as just described. The composition of matter employed in the present invention differs from the foregoing in that it is designed for application to the coated material at some time subsequent to the manufacture of the binding material itself, and lends itself to the application to binding material even after the latter hasbeen converted into book covers, whereas in the prior art mentioned above the unique properties of the material result from a finished coating applied as an integral step in the manufacture of the product.

The invention has as an object the production of a suitable composition which, when applied to the surface of a cellulose derivative coated material or other bookbinding materials commonly known as book cloth, will permit two surfaces of such material to be adhered to each other or allow adhesion of paper, fabric or similar materials to such treated fabric surfaces by means of the use of regular bookbinding adhesives such as glue or paste.

A further object is to render such bookbinding materials coated with cellulose esters, e. g. cellulose acetate and cellulose nitrate (pyroxyline), as described, readily adaptable to stamping with genuine gold leaf and other metallic foils by means of suitable heated dies or type without any treatment of the surface of either the binding material or the metallic foils.

These objects are accomplished by the following invention which consists of the application of a composition which serves to reduce the interfacial tension between the two surfaces to be adhered, and is of such a nature as to soften upon heating, permitting satisfactory anchorage of genuine gold leaf and other metallic foils, returning to its' original state upon cooling, thus forming a strong bond between the metal leaf and the surface of the binding material.

This invention in its accomplishment resides in the choice of suitable ingredients for a sizing composition which will reduce the interfacial tension between the two surfaces tobe adhered so as to allow the use of aqueous dispersed adhesives. The following examples are given in order that the method of producing the results of the invention may be clearly understood. The following solutions are prepared:

From these solutions there is then made up the following composition:

Percent Solution A 22.7 Solution B 34.1 Butyl acetate 31.8 Dibutyl phthalate 11.4

The finished composition then contains the following:

Percent I Shellac 3,54; 5 Gum copal 5.32 Denatured alcohol 47.94 Butyl acetate 31.8 Dibutyl phthalafe 11.4

A sizing composition having approximately the following composition by weight may be similarly prepared:

Percent Shellac- ,5 Gum sandarac 5 Butyl aceta e 212.5 Ethyl acetate 22.5 Denatured ethyl alcohol 3:0 Tricresyl I phosphate '15 is withdrawn. The amount of solid material in each dispersion is carefully determined by analytical procedures used in the art and the dispersion brought to the proper concentration by the addition of alcohol if necessary.

A shellac and gum copal dispersion in alcohol cannot be used alone. In a very humid atmosphere the alcohol is apt to absorb water which turns the shellac and gum white,this is known as blushing. -in the art. Dibutyl 40 phthalate is also added to render the film soft and pliable and to prevent the composition from sticking to the operators fingers.

The total quantity of the combined resins in the above example can vary between 345% by weight. The copal may vary from 5-95% and the shellac from 95-5% of the weight of the combined resins; Percentage of the solvent may be varied so as to give any desired fluidity.

This will be readily apparent to those. versed in the art of compounding sizing compositions.

No restriction in the above composition is made to the use of the combination of shellac and gum copal. Other gums such as kauri, sandarac and accroides, rosin, ester gums, and

other natural or synthetic resins may be substituted for all or part of the gum copal. Where a light colored sizing composition is desired, bleached shellac may be used in place of orange shellac.

As other softeners in place of dibutyl phthalate, tricresyl phosphate, amyl stearate, or diamyl phosphate have been found to be equally as satisfactory. While butyl acetate for the anti-blushing component is preferred, other high boiling solvents such as amyl acetate, di-

ethylene glycol-monobutyl ether, mono-ethyl ether of ethylene glycol, or similar materials may be used.

As the dispersing medium for the gums, a

volatile organic solvent, e. g. denatured alcohol United States Revenue Bureau Formula 23'-A,

which consists of one hundred parts by volume of ethyl alcohol and ten parts by volume of CP acetone, has been found to be satisfac- 76 tory, although other completely or specially deapproximately the following composition by natured formulas may be used. Methyl alcohol may be used in place of the ethyl alcohol if desired. Part of the alcohol may be replaced by such dispersing media as ethyl acetate, ethyl propionate and similar esters. 5

The composition described above and modifications thereof find varied uses in the bookbinding and similar arts such as. application to artificial leather, book cloth, etc., bound books, and as a size for decorating with genuine gold leaf and other metallic foils. Also, it finds extensive application as an interfacial tension reducer for two surfaces to be adhered especially in the bookbinding art Where leather substitutes are used for adhering the end sheet to the turn-in on the book cover, or as an adhesive for cementing two surfaces of cellulose derivative coated materials or to adhere paper or fabric to such materials.- Its use is extended where such problems as just noted are met, for an example in the manufacture of lugga e, optical cases, typewriter cases, etc.

This invention presents as an advantage over previous compositions used for a similar purpose the fact that the particular combination of resins and softeners yields a flexible film which suitably reduces the interfacial tension so asf to allow proper adhesion with aqueous adhesives and which does not become brittle and shatter causing the surface to which it has been applied to turn white and'become unsightly in addition to giving a poor bond between the surfaces to be adhered. Another distinct advantage is that it permits the application of gold leaf by either power presses or hand pallet stamping between a much wider temperature range than is possible with the sizes used at present. A temperature of from F. to 350 F. has been found possible with the size of this invention. In contrast to this wide range, the common sizes now used possess a very narrow working temperature range. Further advantage is that it permits its use either as a size for adhering two surfaces, or asv an adhesive for two surfaces without any previous treatment of the surface. This is not possible with the sizes in use at present. The size also renders the binding mold proof.

It is apparent that many widely different embodiments of this invention may be made without departing from the spirit and scope thereof and therefore it is not intended to be limited except as indicated in the appended claims. v

I claim:

1. In the treatment of fabrics coated with a cellulose derivative composition, the step of superposing on said composition a size having weight: 60

Per cent 3.54: 5.32

Shellac Gum copal Denatured alcohol 47.94 Butyl ace 31.8 Dibutyl phthalate 11.4

2. A sizing composition having approximately the following composition-by weight:

I Per cent Shellac 3.54 Gum. copal 5.32 Denatured alcohol 47.94 Butyl acetate 31.8 Dibutyl phthalate 11.4 75

3. A sizing composition having approximately the following composition by weight: 7

Per cent Shellac 5 Gum sandarac 5 Butyl acetate 22.5 Ethyl acetate 22.5 Denatured ethyl alcohol 30 Tricresyl phosphate 15 4. A sizing composition for coating cellulose derivative coated fabrics containing between 3 and. 15% by weight of a resin mixture consisting of from 95% to 5% of shellac and from 5% to 95% of at least one resin taken from the group con- 15 sisting of gum copal, kauri, sandarac, accroides,

rosin and ester gum, a volatile organic solvent therefor, and a plasticizer.

5. A bookbinding fabric, thermo-plastically adhesive to metallic leaves, comprising a base ma- 20 terial coated with a cellulose derivative and sized with a composition containing from 3 to 15% by weight of a resin mixture consisting of from 95% to 5% of shellac and from 5% to 95% of at least one resin taken from the group consisting of gum copal, kauri, sandarac, accroides, rosin and ester gum, an anti-blushing high boiling solvent, a lower aliphatic alcohol, and a softener.

6. A bookbinding fabric thermo-plastically adhesive to metallic leaves, comprising a base material coated with a cellulose derivative and sized with a composition having approximately the following composition by weight:

Percent 35 Shellac 3. 54 Gum copal 5.32

Denatured alcohol 47. 94 Butyl acetate 31. 8 Dibutyl phthalate 11.4 40 7. A bookbinding fabric thermo-plastically adhesive to metallic leaves, comprising a base material coated with a cellulose derivative and sized with a composition having approximately the following composition by weight:

8. The process which comprises applying a metallic leaf to a bookbinding material coated with a cellulose derivative and sized with a composition containing from 3 to by weight of a resin mixture consisting of from 95% to 5% of shellac and from 5% to 95% of at least one resin taken from the group consisting ofgum copal,

kauri, sandarac, accroides, rosin and ester gum,

an anti-blushing high boiling solvent, a lower aliphatic alcohol, and a softener.

9. The process which comprises applying a gold leaf to a bookbinding material coated with a cellulose derivative and sized with a composition containing from 3 to 15% by weight of a resin mixture consisting of from 95% to 5% of shellac and from 5% to 95% of at least one resin taken from the group consisting of gum copal, kauri, sandarac, accroides, rosin and ester gum, an antiblushing high boiling solvent, a lower aliphatic alcohol, and a softener.

10. The process which comprises applying at a temperature of 150 degrees F. to 350 degrees F. a metallic leaf to a bookbinding material coated with a cellulose derivative and sized with a composition containing from 3 to 15% by weight of a resin mixture consisting of from 95% to 5% of shellac and from 5% to 95% of at least one resin taken from the group consisting of gum copal, kauri, sandarac, accroides, rosin and ester gum, an anti-blushing high boiling solvent, 2. lower aliphatic alcohol, and a softener.

11. The process which comprises applying at a temperature of 150 degrees F. to 350 degrees F. a gold leaf to a bookbindin'g material coated with a cellulose derivative and sized with a composition containing from 3 to 15% by weight of a resin mixture consisting of from 95% to 5% of shellac and from 5% to 95% .of at least one resin taken from the group consisting of gum copal, kauri, sandarac, accroides, rosin and ester gum, an antiblushing high boiling solvent, a lower aliphatic alcohol, and a softener.

12. The process which comprises applying gold leaf to a bookbinding material coated with cellulose nitrate and sized with a composition containing from 3 to 15% by weight of a. resin mixture consisting of from 95% to 5% of shellac and. from 5% to 95% of at least one resin taken from the group consisting of gum copal, kauri, sandarac, accroides, rosin and ester gum, an anti-blushing high boiling solvent, a lower aliphatic alcohol, and a softener.

13. In the treatment of fabrics coated with a cellulose derivative composition, the step of superposing on the said composition a size containing from 3 to 15% of a resin mixture consisting of from 95% to 5% of shellac and from 5% to 95% of at least one resin taken from the group consisting of gum copal, kauri, sandarac, accroides, rosin and ester gum, a high boiling antiblushing solvent, a. lower aliphatic alcohol, and a softener.

DONALD A. RANKIN. 

